Solid hand held skin cleaning compositions have been marketed for decades. Liquid skin cleansing compositions have made some inroads into sales of solid compositions, particularly in certain geographical areas. However, solid skin cleansing compositions, particularly bars, remain a preferred vehicle for skin cleansing worldwide.
In order to maintain and enhance continued sales of solid skin cleansing compositions, various improvements have been made such as use of mildness enhancing agents such as certain surfactants, free fatty acids, and the like as well as skin benefit agents and conditioning agents such as cationic polymers and oily material such as mineral oil and petrolatum. Efforts to make these bars more attractive such as translucent and transparent bars are also available. Particles such as mica, bismuth oxychloride, kaolin and the like have also been added to these compositions in order to enhance their attractiveness.
In an attempt to create striations in soap, U.S. Pat. No. 4,879,063 discloses a method for preparing a striated translucent bar utilizing a perforated plate situated next to and downstream from the spider, the part in the extruder which holds the screw in place. U.S. Pat. Nos. 5,196,131 and 5,242,614 disclose a soap having the alleged appearance of a polished wood grain prepared using a perforated plate situated next to and downstream from the spider and producing striations in the bar with an iron oxide coated micaceous pearlescent pigment which is oriented generally unidirectional. As aforestated, the perforated plate is next to the spider holding down the end of the screw. Translucent soap bars are clearly preferred over opaque because the resulting wood grain appearance is brighter and sharper. However, it is believed that in no situations are there clear, uniform and relatively thick striations, which can be observed by the human eye.
We have discovered a method of placing sharp, distinctive striations into a cleansing bar using substantially lower levels of platelet reflecting material than utilized previously and obtaining an even sharper more better defined striation than obtained previously. The benefits occur in opaque as well as translucent bars. The process utilizes a perforated barrier located a substantial displacement from the spider of the extruder. Such placement of the perforated barrier allows the striations to be clear and sharply defined.